Temperature control for rollers subjected to heat



J. J. MAYl-:R

Nav.' 27,- 195e TEMERATURE CONTROL FOR ROLLERS SUBJECTED TO HEAT.

Filed NOV. 24,' 1948 JNVENTVoR. JH/v J.' Mn YER HTTENEY m mEl Nov. 27,1956 J. M 2,772,075

TEMPERATQRE co FOR R Rs SUBJECTED To HEAT Filed Nov. 24' 1 2Sheets-Sheet 2 T 'lI lu- [nl i L J I, 6 \\l| .f

United States Patent TEMPERATURE CONTROL FOR ROLLERS SUBJECTED T HEATJohn J. Mayer, Wood-Ridge, N. J.

Application November 24, 1948, Serial No. 61,789

3 Claims. (Cl. 257-95) My invention relates to temperature control andmore particularly to means and/ or method for maximizing heat transferin components employed for treating heated material by the applicationof a refrigerant to the components.

In machines or apparatus for treating or processing mastic or similarmaterials, rotating hollow cylindrical rolls are usually employed togauge a mass or blanket of the material to conform to a specific size orto other- Wise Itreat the material in accordance with a preestablishedprocess. Inasmuch as the temperature of the material being treated orprocessed is such that it effects heating of the rolls above atemperature deemed conducive to satisfactory processing, refrigerants,for instance, cold water, brine, etc., are utilized and introducedwithin the rolls for cooling the latter. This invention, in its solutionof the problem of heat transfer, involves consideration of numerousfactors many of which have been ignored or unrecognized in previousattempts to properly cool mill, calender and other rolls. The functionis not to cool the stock being worked by the roll, but rather, tomaintain the roll at a low enough temperature so it can be kept incontinuous operation without becoming overheated. The metal of the rollconducts heat readily. Therefore the thickness of the roll does notintroduce a limiting factor. But the inside surface is of primeimportance. For purpose of strength, the rolls have thick walls andconsequently the inside surface area of the roll is far less, usuallyabout half, the outside surface area. To maintain heat equilibrium, heattransfer from the inside area therefore must be increased to equal theheat transfer received from the stock by a proportionately greateroutside area. Mere flow of fluid within the roll does not attain thisdesired cooling. Unfortunately an insulative film of the fluid forms onthe inside surface of the roll. This is because, as smooth as the insidesurface of the roll may seem, microscopically it reveals mountains andvalleys which entrap the molecules of the cooling uid. The lms trappedin the valleys quickly become hot, and since they are not constantlyreplaced with cool films or layers, they quickly form and `remain as aninsulative film which slows down heat transfer from the roll to thetransitory uid beyond said film. Based on these factors, the presentinvention presents construction and method primarily directed to theelimination of the insulative film normally entrapped in the valleys ofthe inner surface of the roll.

In addition to the formation of film due to the valleys in the innerwall surface of the roll, there are other factors the presence of whichalso tends to form and increase the thickness of the insulative film.One of these film-forming factors is inherent to the roll constructionwhich, because of greater inside diameter thereof than diameter of thefluid outlet, forms a basin or sump wherein 'a considerable volume ofliquid always remains liquid remain in a state of quiescence or at themost,

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affected only by a very sluggish tlow toward the exit. The presentinvention recognizes this inherent detrimental structural andoperational characteristic of prior art rolls and provides a means andmethod of overcoming the same by both creating turbulence in the liquidin the basin-like hollow of the roll and by displacing trapped liuid inthe surface valleys while submerged.

Another of said factors, the presence of which tends to form andincrease the thickness of the insulative film, is the operation ofcentrifugal action forcing the liquid against the inner wall of the rollso that a very considerable thickness of the liquid becomes fixed withrespect to the roll and just revolves with or follows the roll withoutdislodgement even when carried to zenith location above the pool in thebasin-like hollow of the roll. This centrifugal action is exceedinglydetrimental to the cooling procedure, since it not only tends to lodgeand retain the fluid more securely and immobily in the valleys in theroll inner surface, but results in a very considerable increase in thefilm thickness, thereby adding greatly to the insulative effect adverseto the desired heat transfer from the roll to the discharging coolant.According to the present invention, the e'ects of this centrifugalaction are decreased and largely overcome.l

This objective is achieved by use of jets of cooling uid having a strongdownward velocity carrying the jets through the fluid in the basin-likehollow to the roll inner wall thereby both forming :a barrier transverseto the rotational direction of the roll and functioning to extract uidtrapped in the inner surface valleys.

In addition to the essential objects of the invention indicated above,another object of my invention is to provide means of the foregoingdescribed character capable of being incorporated in rolls havingboresof :a relatively small diameter.

A further object of my invention is to provide means of the foregoingdescribed character capable of being incorporated in rolls already inuse without modifying the rolls.

An important object of my invention is to provide a roll of theforegoing described character which is so constructed and arrangedY asto limit the refrigerant content to a predetermined amount and equippedwith means effective for agitating the content and to preclude formationof an endless coating path about the interior peripheral surface of theroll.

Another important object of my invention is to provide means of theforegoing described characterwhich is simple in construction, durable inuse, efficient in operation, economical in Imanufacture and easy toassemble and disassemble.

With the above and `other objects in View, as will hereinafter appear,the invention consists in the combination and arrangement of partshereinafter set forth'and illustrated in the accompanying drawings fromwhich the several features of the invention and the advantages attainedthereby will be readily understood by those skilled in the art.

Referring to the drawings wherein like reference char-v acters designatelike parts throughout the several views:V

trunnions' 40 -and '-11, '-respectively. The trunnions are adapted -tobe rotatably journaled in bearings to permit rotation of the rollwhich-constitutes a component .oan apparatnsgor machine fortreatingortrprocess'ing 'heated `mastic `material or lthe like, tit beingunderstood Vthat the-temperature'of the material being' treated orprocessed issuch tlratjt causes heatingof the roll above a `ternperaturedeemed conducive .to satisfactory processing.V

, Thetrunnion It) Ais provided with a centraiized opening or passagelZextending therethrough and'haing 'its Outer end `diarnetricallylenlarged as at i3 and itsfinner cndcommunicating 'with the chamber I6through the end Vwall 8. The opening V12 Vconstitutes an outlet'rneansorjpassage having an apprecibly Vsmaller diameter than the :chamber :6as a result of which'tbe hollow of the roll forms a sump or "basin, 'in'the nadir zone of the harnber, "lower than the .outletpassage 12 andtherefore will retain a :pool of 'the refrigerantY or liquid therein.'The outer end of the `trunnion ldhasrsecured thereto a`stu"l`flng1boxor gland I3 'through which extends` a conduit -or 'tubular casing 14communicating with the end 'i3 ofthe passage l2, thestufiing box orgland serving `asa seal *andperrnitting rotation of the roll 5 relative`to the casing 154. The outer end section of Vthel'casing 14 2 hasconnected thereto `a radially extending outlet pipe 15 and ispr'ovide'dwith Va radial end wallthrough which extends a'refrigerant supplyconduitlt).

The-.refrigerant supply conduit'Z .is provided with fa pair of sections"21 and 22 with .the section .21be1ing tubular and extending through.the passage 12 into 'the casing i4. The section 22, which maybestructurally integrally "formedwith the section 21, is disposed withinthe chamber i6 and is substantially'ovato-oblongintransversali'ty'to'providepairs of oppositely disposed plane'and-arcu'atewalls and'has lits outer end, .adjacent'the end .wall

9., closed. The arcuater walls constitute Asidewalls 22 which aredisposed appreciably out of the axially projected outer circumferentialconnes'of the section I21 while theplane walls constitutespaced'upperandlower 4o' Walls 23 and 24, respectively, and `are disposed Vwelllwithin 'said contines.

The upper wall .23'has mounted .thereon a plurality of fspacedspray'heads '25 of .the l'high velocity "type whereby `sprayed Ystreamsyof refrigerant or cooling' liquid, under pressure, from the conduit 20,will be impelled against the inner wall of the rollor peripheral face`of the'chamber in the zenithal zone thereo'f so forcibly asto'penetrate intothe valleys o'flthe inner sur-- face of the roll andbreak up, dislodge 'and dispersethe 50 heat-insulating lm. ,Itis to beunderstood lthat 'th'espray l heads '25 are constructed and spacedinamanner causing the spray streams to fan outward and roverlap orintermingle "in their approach y-to the vroll wall so "that 'the seriesof spray streams from the several Vspray heads willprovide anuninterrupted expanse of lmfpunctur'ing and '-dispersing streamthroughout the length l of the zeni-Y Y tha'l zone between end walls 8`and 9.

`The lower wall '24 of "conduit vsection 22 .'is provided with aplurality 'of jet Vnozzles 26, of the high-velocity typejwherebya row'of'high pressure jetsofrefrigerant VIor cooling liquid from the conduit20 will be .directed toward and 'will `pierce the pool of duid to the5bottom thereof and will forcibly impinge 'againstitlre inner surfaceofthe Vroll within the basin or sump, the force `ot' thejjets beinggreat enoughjto `lboth agita'te`.tl1efp'oci'l of refrigerant contained-within `the :sump `and 'to Aalso irupture and 'disperse the` lm on thewall 'oftheroll at the bottom ofthe pool. `ltmay 'also belrerementioned-that the spray heads 25 and jet .nozzles .26 arearranged.at top and lbottom respectively of #the conduit vsection 122, and:alternate in longitudinal location, and thus '-coact .to resist'displacement 'of the S.conduit section within 'the'chardherfrom'reactionaryforce of .the ejected streams.

"'jy'utihinglliigh velocity 'jet.jnozz`les ,'l electively disrupt,within Ithe nadiral zone, that portion of the re- `frigerant which hadeither become 'quiescent'for which had established anity toward thesurface from centrifugal action 'or which had established aheat-insulating lrn next said surface by reason of the depth of thepool, or by reason of the rotation of the roll and centrifugal force orby reason .-of the inherent presence of valleys in the roll surface. Theimpinging of the jets against Ithe -innersuace of ythe roll is A-eeQted'with vsuch force as to deflect the Ajets laterally Aover adjacent por.

tions of the surfac'eandjthus'extend.thejlm-disrupting effect over aconsiderable area. It' is furtherpointed out thatr'the-jets-'coactftogether toestalilish'a id in a plane radial to endlongitudinalof :the conduit section and extending from theV conduitsection to'the inner sur@ face of the roll. thereby interrupting'ordislodging the lm or layers of Huid from following 'the rotationalimpulse of ,the roll under 'inuence .of centrifugal retention.

and is .thus .disposed in a plane in .parallelism with .the axis of theroll and superjacent thereto whentheroll is disposed horizontally, :asclearly illustrated .in .the drawings. By thus .mounting the conduit .incloser .re-

lation to 'the zenithal zone of the chamber, vthe'jet nozlation totheconduit; .insome 'instances .the ,passage `being Y.

only 2'1/2'" and the conduit, as fordinarily constructed, approximately7A11/2 it will'be apparent that the distances the .heads andnozzlesproject outwardly 'from the Leon-V i duit must'be less .than l" in.order to permit insertion ofV theV conduit with the 'heads' and.nozzles .assembled .there-V on. V"Obviously, in these "instances, .onlyrelatively .small heads and :nozzles could be :employed .-and which, inpractice, .would 'be ineicient. Y

However, the spec'ic .construction .of the section .22

' f .the conduit as .'here'in disclosed with .respect .to the spacing ofthe walls 23 and 24, permits the ruse @ofimater'ia'lly 'larger and more-etective -heads and .nozzles than would yordinarily 'he .feasible .inview of .the relatively small 'diameter of the passage `andthe ,factthat (the. rolls 4'areordinarily :of a .one-piece .cast constructionwith-V outrelatively/large 4removable components to .permit ac cess 'tothe chamber 6. It 'is to be understood, that l.the

. refrigerant is 'introduced .into -the conduit 20 `under .an

eiectivepressure .and .that the .overflow .of .refrigerant from ,the:sump will pass outof'fthechamber'.throughthe Y In actual .reduction Yto practice, .I have ascertained that in .comparison with.

. the ordinary method, wherein .a .roll has .incorporated passage .12,ycasing and outlet pipe.

therein .a ,refrigerant supply pipe .of .ordinary construction .equippedwith relatively .low velocity spray means, that .the `heat transfer .in.the same roll hav'ing -my -in-V vention incorporatedltherein isincreased more Athan .live

. times over .the ordinary .method and .under the same operatingconditions. Furthermore,`by theuse .of .my

invention, coating jis not only .ruptured and .dispersed from'.the.mounds .on .the surface' f vthe chamber, *but* actually from withintheindentations 'between fthe mounds 1t isgto'be understood .thatthelanguag'e used "herein islintended to cover all the genericlandspec'iic eaturesQo'i the Iinvention .herein described, 'andallstatements .df ,thes'cope o'f theinvention which, "as 'a-.rnatteroflanguage, maybe said to 'fall therebetween. `Fur- The conduit .is.eccentrically mounted within the .ro/ll.

purpose of description and not by way of limitation, it beingunderstood, in some instances, that the various components may bearranged in a manner whereby the foregoing terms would not appropriatelydescribe their relative positions.

Without further elaboration, the foregoing will so fully explain theinvention that others may, by applying current knowledge, readily adaptthe same for use under various conditions of service. Moreover, it isnot indispensable that all the features of the invention be usedconjointly since they may be employed advantageously in variouscombinations and subcombinations.

It is obvious that the invention is not coniined to the herein describeduse therefor as it may be utilized for any purpose to which it isadaptable. It is therefore to be understood that the invention is notlimited to the specic construction as illustrated and described, as thesame is only illustrative of the principles involved which are capableof extended application in various forms, and the invention comprehendsall construction within the scope of the appended claims.

What I claim is:

1. In combination with a heat exchange hollow roll having a peripheralworking surface, the temperature of which is to be controlled, andhaving an inner cylindrical wall the surface whereof has microscopicvalleys conducive to formation of liquid film and said roll havingpartial end walls adapted to retain a pool of liquid in the roll,whereby as the roll rotates part of said cylindrical wall is submergedin and part is above said pool, means for injecting concentrated, highvelocity jets of duid on the submerged part of said wall, and means fordirecting high velocity sprays of uid upwardly away from the pool fordispersing film on a part of said wall above said pool.

2. In combination with a material treating roll of a type provided witha cooling chamber defined by a peripheral wall and a refrigerant outletpassage communicat ing with said chamber above the bottom thereofwhereby the nadiral zone of the chamber constitutes a refrigerant sump,said wall having an inner face on which refrigerant introduced into thechamber tends to form a film during rotation of the roll and thusestablish a surface seal on said face to render refrigerant, engagingsaid seal, ineective for cooling said wall below a denite temperature; arefrigerant supply conduit extending through said passage disposedwithin said chamber and equipped with refrigerant high velocity sprayheads effective for directing refrigerant sprays from said supply meansagainst said face within the zenithal zone of said chamber and withsufficient force to counteract said iilm, and refrigerant jet nozzleseiective for directing refrigerant jets from said supply means throughrefrigerant in said sump and against said face with sufficient force toagitate refrigerant in said sump and to rupture and remove film on saidface, whereby, refrigerant from said supply means is rendered eiectivefor cooling said wall below said temperature, said heads and nozzlesbeing arranged in opposed relation to counteract reaction by said spraysand jets and maintain said conduit against displacement.

3. In combination a heat exchange hollow roll having a peripheralWorking surface, the temperature of which is to be controlled, means fordistributing a cooling uid Within the roll comprising an inlet conduitpositioned Within the hollow portion of the roll and spaced from theinner surface thereof, the said conduit being provided with a pluralityof spaced, aligned high velocity spray heads on one side thereof andwith a plurality of spaced, aligned high velocity jet nozzles on thelower side thereof; means positioned at an end of the roll whereby thecooling uid may be drained from the roll, the said means comprising atrunnion having a passage extending therethrough communicating with thehollow portion of the roll, the diameter of the passage being smallerthan the diameter of the hollow portion of the roll to provide a sumpwithin the roll, and the diameter of the passage being larger than theexternal diameter of the conduit; and wherein a stuiiing box is securedto the outer end of the trunnion, through which box extends a casingprovided with a drain outlet and having substantially the same internaldiameter as the trunnion passage and communicating therewith; andwherein a portion of the conduit is positioned centrally of the casingand trunnion passage to thereby permit fluid from the roll to bedischarged through the trunnion passage, casing and outlet pipe.

References Cited in the file of this patent UNITED STATES PATENTS1,564,171 Brown Dec. l, 1925 1,783,465 Fox Dec. 2, 1930 1,819,988 JonesAug. 18, 1931 1,820,074 Kilborn Aug. 25, 1931 2,435,959 Eaby Feb. 17,1948 FOREIGN PATENTS 438,490 Germany Dec. 18, 1926

